Mukhtasar Bukhari

Narrated from Sayyiduna Anas bin Malik (may Allah be pleased with him) that the Noble Prophet (peace and blessings of Allah be upon him) saw some spittle in the direction of the Qiblah, and it was displeasing to him. So much so that (the effect of anger) appeared on his blessed face. Then he (peace be upon him) stood up and cleaned it with his own hand. Then he said: "When any of you stands in his prayer, he is conversing with his Lord, or (he peace be upon him said) his Lord is between him and the Qiblah, so he should not spit in the direction of the Qiblah, but rather to his left side or under his foot." Then he (peace be upon him) took the edge of his sheet, spat in it, and rubbed it, and said: "Do like this."